184 THE NEW KNOWLEDGE. 



ceeds the mass of the particle when at rest, and the third 

 column the same values as found by Kaufmann experi- 

 mentally : 



Number of times the 

 mass of the particle 



with the given ve- 

 locity exceeds its 

 mass at rest. 



ditto. 



Velocity of the Mathematically Found by experi- 



particles. determined. ment. 



2.85 3.1 3.09 



2.72 2.42 2.43 



2.59 2.0 2.04 



2.48 1.66 1.83 



2.36 1.5 1.65 



We see from these results that the calculated and the 

 experimental results practically agree, and we are, there- 

 fore, entitled to believe, if we like, that the whole mass of 

 the corpuscle arises from its electrical charge. But the 

 corpuscle we deem to be the constituent of an atom, the 

 atom the constituent of a molecule, and a molecule 

 the constituent of a mass of matter, such as a table or a 

 chair. Hence, on this view, the inertia of any material 

 body, and the mass of it as measured by the inertia, is 

 due simply to electrical charges in motion. On this view, 

 then, the to-and-fro motion of a pendulum and the electrical 

 oscillations of the spark from a Ley den jar, are simply two 

 manifestations of an identical thing, the inertia of a 

 charged body. 



But what do we mean by saying that the mass of a 

 body depends simply on an electric charge? By mass is 

 meant quantity of matter, and the idea that the quantity 



